Question

Which of the following is diamagnetic
(A) $ H{e_2}^ + $
(B) $ {H_2}^ - $
(C) $ {H_2}^ + $
(D) $ {H_2} $

Answer 1

Hint :Diamagnetism is a quantum mechanical phenomena that occurs in all materials and is referred to as diamagnetic when it is the only contribution to magnetism. The weak diamagnetic force in paramagnetic and ferromagnetic materials is overcome by the attractive attraction of magnetic dipoles in the material.

Complete Step By Step Answer:
Some materials are weakly attracted by an externally applied magnetic field and create internal, induced magnetic fields in the direction of the applied magnetic field, which is known as paramagnetism. Diamagnetic materials, on the other hand, are repelled by magnetic fields and create induced magnetic fields in the opposite direction of the applied magnetic field.
A magnetic field repels diamagnetic materials because it induces an induced magnetic field in them in the opposite direction, resulting in a repulsive force. Magnetic fields, on the other hand, attract paramagnetic and ferromagnetic materials. The magnetic permeability of diamagnetic materials is smaller than that of vacuum, which is zero. Diamagnetism is a faint effect that can only be seen by sensitive laboratory instruments in ordinary materials, but a superconductor serves as a powerful diamagnet since it repels a magnetic field completely from its core.
Number of electrons in $ H{e_2}^ + $ = 3 Hence they are paramagnetic in nature.
Number of electrons in $ {H_2}^ - $ = 3 Hence they are paramagnetic in nature.
Number of electrons in $ {H_2}^ + $ = 1 Hence they are paramagnetic in nature.
Number of electrons in $ {H_2} $ = 2 Hence they are diamagnetic in nature.
Hence option D is correct.

Note :
To identify whether a particle (atom, ion, or molecule) is paramagnetic or diamagnetic, chemistry uses a simple rule of thumb: The material comprised of this particle is diamagnetic if all of its electrons are coupled; it is paramagnetic if any of its electrons are unpaired.